Definitely P. amilis.
Why would you want to be rid of it? P. amilis is adorable, putting on a great show for a few months, if you're paying attention between 8 to about 11:30 AM.
But if you do, they pull up easily if the ground is not too dry.
Portulaca oleracea 'Granatus' is P. umbraticola.
This plants is P. umbraticola:
Portulaca oleracea Mojave® Tangerine